tty /T-T-Y/ [UNIX], /tit'ee/ [ITS, but some UNIX people say it this way as well; this pronunciation is not considered to have sexual undertones] n. 1. A terminal of the teletype variety, characterized by a noisy mechanical printer, a very limited character set, and poor print quality. Usage: antiquated (like the TTYs themselves). See also bit-paired keyboard. 2. [especially UNIX] Any terminal at all; sometimes used to refer to the particular terminal controlling a given job. 3. [UNIX] Any serial port, whether or not the device connected to it is a terminal; so called because under UNIX such devices have names of the form tty*. Ambiguity between senses 2 and 3 is common but seldom bothersome.